Methods and systems for improving the visibility of details in an image, are known in the art. For example, a conventional thermal image is provided, as arrays of values, each representing a different temperature. Conventionally, a visible space (e.g., grayscale or RGB) is assigned to these values, enabling the user to view the thermal information visually, and not as a set of values.
U.S. Pat. No. 6,033,107 to Farina et al entitled “Temperature mapping system”, is directed to a system and method for deriving a high resolution, two dimensional graphic representation of the surface temperature of an object. The system uses the light polarizing properties of a nematic liquid crystal (NLC) material to indicate the temperature of an electronic component, such as an integrated circuit (IC). The surface of the electronic component is coated with the NLC material. A temperature control platform, on which the electronic component is mounted, varies the temperature of the electronic component through a range of temperatures. The temperature at which the NLC material changes phase is between the lower limit and the upper limit of the range of temperatures. An optics element captures a sequence of images of the electronic component, using light reflected by the NLS coated surface and passing through a cross polarizer. Each of the images depicts a two dimensional representation of the surface at a certain temperature within the range of temperatures. A computer system stores a digital representation of the sequence of images, processes the image sequence, and constructs a color-coded thermal map of the surface temperature distribution of the electronic component. An algorithm defines the intensity signature of valid “hot spots” in selected images, and determines the location of the hot spots on the surface as a function of the intensity signature. The selected images are determining by detecting the first image in a sequence to have a dark spot, and identifying the temperature corresponding to the first image, thereby determining the temperature at which the NLC material changes phase.
The potential hot spots in the image are detected by binarizing the pixels in the image, so that each pixel is designated as either a hot spot pixel or a non hot spot pixel. In particular, each pixel is compared to a threshold range, and then the pixel is designated as a hot spot pixel if it falls within the designated range. Each potential hot spot pixel is verified, by comparing consecutive images and eliminating hot spot pixels not having a hot spot pixel in the corresponding location in a succeeding image. The potential hot spot pixels are further verified by adding pixels at corresponding locations of the selected pixels, producing a resulting pixel with an integer value representing the number of images having hot spot pixels at that corresponding location. The resulting pixel includes an integer value corresponding to an assigned temperature, and being represented by a predetermined color. The resulting pixels are used in constructing the color-coded thermal map of the surface temperature distribution of the electronic component.
U.S. Pat. No. 4,520,504 to Walker et al entitled “Infrared system with computerized image display”, is directed to a system which generates computerized display images of infrared scenes. The system includes an infrared scanner, a tape recorder, a digitizer, a computer, a display generator, and a television monitor. The infrared scanner collects infrared radiation emitted from an object, such as a structure exhibiting heat flow across its surface (e.g., reactor piping, power cabling). The infrared scanner converts the radiation into a real-time visual image, the intensity of which is a function of the intensity of the measured infrared radiation. The visual image provided by the infrared scanner cannot be calibrated nor saved for later use. The tape recorder records the detector output of the infrared scanner, in the form of analog signals for pixels in frames with a scanning raster. The digitizer receives the analog signals and generates corresponding digital signals for each pixel, each digital signal being a function of the intensity of the infrared radiation measured from the object. The computer receives the digital signals, and performs processing which involves at least surveying all pixel brightness values, and identifying maximum and minimum values. The display generator creates a display frame from the digital signals. The display frame is sent to the television monitor, which displays an image of the object. The television monitor further displays a grey scale alongside the image, to provide calibrated quantitative information related to the temperature at different locations of the object.
U.S. Pat. No. 6,868,171 to Souluer entitled “Dynamic color imaging method and system”, is directed to a method and system for creating color images displaying variations of tissue density over selected regions to facilitate detection of tissue anomalies. The system includes a controller, a detector, a locator and a camera. The detector collects data related to tissue characteristics. The characteristic data may relate to a single property of the tissue (e.g., tissue density), or to a combination of properties (e.g., tissue density, tissue temperature, tissue color). The locator collects data related to the length and width dimensions of the patient relative to a location pattern on the platform on which the patient is positioned. The locator further collects data related to the length and width dimensions of the detector relative to the tissue of the patient and to the location pattern. An optical head on the locator collects data related to height dimension of the detector relative to the tissue of the patient. The camera provides an image of the tissue of the patient, and collects data related to the length and width dimensions of the tissue relative to the image.
The controller receives the image from the camera and divides the image into predetermined portions. The controller receives characteristic data of the tissue from the detector for each portion of the image. The controller associates a color, or a shade thereof, to incremental values of the characteristic data for each portion of the image. The color displayed for each portion of the image portrays the degree of variation of the value of the characteristic data relative to the characteristic data value for other portions of the tissue. The system displays the color for each portion of the image on a monitor or display screen.
The controller uses the data received from the locator to monitor the position of the detector relative to the tissue, and to associate the position of the detector to each portion of the image. The controller may further use the height data from the optical head, to allow recording of the characteristic data in three dimensions, and to create and display a three-dimensional image of the tissue characteristics. The system may further compare recorded characteristic data for coordinates of the tissue with previously determined characteristic data for the same coordinates of the tissue. The system displays an image of the tissue, and assigns a color to each portion of the image based upon any degree of change in the characteristic data for that portion of the image. The change displayed may be an absolute difference in the compared characteristic data, a first derivate analysis, or a combination thereof.
U.S. Pat. No. 5,012,333 to Lee et al entitled “Interactive dynamic range adjustment system for printing digital images”, is directed to a method and system for processing an image of a wide dynamic range scene, such that the printed image resembles the original scene. The method is based on an understanding of visual photoreceptor adaptation and human visual contrast sensitivity. A processor receives a digitized image captured by an image scanner. The processor transforms the red, green, blue (R,G,B) components of the image to the luminance and chrominance components. A low pass filter extracts the low frequency component of the luminance image component. The low frequency component is mapped to a normalized density through a dynamic range adjustment curve, which adjusts the contrast of the low frequency component. In particular, a given pixel is printed darker by subtracting a fraction of the averaged surround density from the density of the pixel. The surround of the pixel is the weighted average density of all neighboring pixels. The fraction of the averaged surround density subtracted from the pixel is selected to be a function of the averaged density (i.e., rather than a constant). The system displays the original digital image next to a dynamic range adjusted image, and may further display the density histogram of the image. The location and amount of compression or expansion of the dynamic range of the printed image may be controlled, by altering the shape of the function. A user may manipulate the function interactively, for example by using the displayed density histogram and the adjusted image as feedback.